Glossary of terms
Absence of living organisms
Stress to living organisms caused by non-living, environmental factors e.g. cold, heat, drought etc.
Substances that contain one or more hydrogen atoms in their molecular structures. Acids have a pH that ranges from 0-6, and react with bases to form a salt.
Acquired Immune Deficiency Syndrome (AIDS)
A disease that allows opportunistic infections to invade the body. A normal body can usually fight off these infections through a healthy immune system, but if it is HIV positive, HIV slowly destroys the immune system. The HIV virus attacks macrophages and helper T cells.
The change or evolution of characteristics or features to enable an organism to survive better in its environment
A purine base that is found in both RNA and DNA. Adenine forms base pairs with thymine in DNA and uracil in RNA.
Adenosine Triphosphate (ATP)
Provides the majority of all the chemical energy required to run the cells of all living things on this planet.
One of two characteristics that may be produced by a gene that is found at a given location on a chromosome.
The single molecular units (20 in total), that when chained together form a protein. The number, type, and sequence of amino acids found in the chain determine the shape and function on the protein.
Substances that are secreted by various species of bacteria and plants. e.g. penicillin, which is secreted by bread mold. Antibiotics are usually secreted as a defense strategy because they are toxic.
When a cell becomes tolerant to an antibiotic that it previously had the ability to destroy.
A sequence of three nucleotides in a transfer RNA (tRNA), that codes for an amino acid. The anticodon is important for protein synthesis.
Is also called the antisense or template strand, and is the single strand of the DNA double helix that becomes transcribed.
A large protein that defends the body against antigens by binding to them so they can be destroyed. They're also called immunoglobulins, and are made by the immune system's B lymphocytes
Anything that is capable of triggering an immune response. Antigens are also called immunogens.
All chromosomes except the sex chromosomes. All cells of the body except the sex cells have two copies of each autosome.
All organisms e.g. plants, that can live on very simple carbon and nitrogen sources, such as carbon dioxide and ammonia.
Bacillus thuringiensis (Bt)
Bacillus thuringiensis are rod-shaped soil bacteria that produce "cry" proteins. These proteins are toxic to some insects because they bind to their stomachs and cannot be digested. The proteins have no effect on mammals.
Microscopic organisms that are easy to identify by their cell wall, and nuclear region. Most bacteria fall under the categories, round, rod-like, spiral, or filamentous unicellular or noncellular, and are often found in colonies.
A segment of the DNA (and RNA) molecules. The four bases that comprise DNA are adenine (A), cytosine (C), guanine (G), and thymine (T).
Base pair (bp)
Two nucleotides that are in different nucleic acid chains. In DNA, the nucleotide bases are adenine (which pairs with thymine) and guanine (which pairs with cytosine).
Any material that can be broken down naturally i.e. by bacteria, fungus and digestion.
The variability of all living things (plants, animals, and microbes) including variation within species, between species and ecosystems.
The collection and storage of information about genomics in databases.
The assessment of the impact and safety of genetically improved/modified organisms and the development of protective policies and procedures for adoption to ensure this.
The use of living things to form or change useful products and tools.
Any uncontrolled or abnormal cellular growth.
An agent that causes cancer.
Any substance that is able to increases the rate of a chemical reaction, without being used up. Enzymes catalyze biological reactions but do not become involved in the reaction.
The unit of life that makes up the living tissue of every multi-cellular organism.
Cells that are grown up and stored outside of living organisms.
Central dogma (new)
Is a statement to add to the original "central dogma" statement. It states that an animal's environment plays an important role by determining which genes will be expressed in the animal's cells.
Central Dogma (old)
States that DNA makes RNA which makes protein.
The constricted ("waist") part of a chromosome that attaches to the spindle during mitosis or meiosis.
The copied arm of a chromosome produced by DNA replication. They consist of coiled DNA around bands of histone protein.
Ribbon-like twists of DNA molecules in the nucleus of the interphase.
A thread like structure of genetic material (genes) made up of a long molecule of tightly coiled DNA. The chromosomes are usually x shaped and usually found in pairs in the cell nucleus.
A genetic copy of a whole or part of an existing human, animal or plant.
A set of three nucleotides within messenger RNA (mRNA) that code for an amino acid (triplet code) or a termination signal.
Complementary DNA strands
Due to the ability for nucleotides within the strands to match-up, two strands of DNA are able to bind to one another.
Too little environmental or nutritional input for physiological functions to take place normally. Sometimes deficiencies can lead to stunted growth or development.
A part of the genetic material is lost from a chromosome.
Deoxyribonucleic acid (DNA)
The chemical building block that carries information to control growth and development as well as all inherited characteristics that are passed on from generation to generation. DNA is found in most living organisms, plants, animals and microbes.
A disease in which the body either does not produce insulin, or the body does not use the insulin it does produce properly.
A process through which a single type of cells (e.g., stem cells) becomes different types of cells with special functions.
In somatic cells each of the chromosomes appears twice, and each pair is a contribution from the organism's mother and father.
Diversity (within a species)
the genetic differences that can be found within a population in a species.
DNA Marker Sequence
A DNA sequence that can almost always be seen each time a certain characteristic associated with a specified trait is seen. This marker sequence is "linked" to the sequence that causes the trait.
Phenotype seen in offspring whether or not the recessive allele is inherited by the offspring.
Transgenic plants that contain agents that are able to trigger an animals immune system.
antibodies that are produced through cells that have been genetically engineering to produce antibodies.
A catalyst that is produced by living cells to allow chemical reactions to take place in cells. Enzymes catalyze only specific types of chemical reactions, and only act on specific substances.
Escherichia coliform E .coli
A bacterium that has been commonly used in genetic experiments, and is normally found in the intestines of humans and other vertebrates.
Chemical compounds that can't be made by a specific organism but are important for the organism to survive.
The gradual change of the genetic make up within a population over a number of generations.
The step to interpret the cell's genetic information into a specific protein.
When the (haploid) male and (haploid) female sex cells or gametes join to make a diploid zygote. In humans this would be between the sperm and the ovum (egg).
A plant-like organism that cannot produce its own food and so feed off other organisms to survive the way parasites do. They belong to a group known as saprophytes.
A unit of the hereditary material (section of DNA), which contains the information for a characteristic or particular protein. Each gene is a stretch of DNA found on a chromosome.
To copy segments of genes within DNA or RNA.
A way of directly manipulating and changing the genetic make up of an organism to produce desired effects/traits and to eliminate undesirable ones.
Preventing or suppressing genes being translated into proteins.
The treatment of disease by replacing or manipulating damaged or abnormal genes with normal ones.
A diagram showing the sequence and position of genes along a chromosome.
Genetically Modified Organism (GMO) or Genetically Manipulated (GM)
Plants, animals or microbes that contain genes which have been altered or transferred from other organisms or species in a way that conventional techniques cannot.
The entire hereditary material (set of genes) in an organism.
Sex cell (sperm or egg), contain only half (haploid) the usual number of chromosomes that other cells contain.
A step to gather/collect microorganisms from a substance. This is usually by a filter or centrifuge.
A spiral, staircase-like structure.
Helper T cells (T4 cells)
lymphocytes that bind B cells if they recognise a foreign particle on the B cells' surface.
Crop plants, that are tolerant to certain herbicides normally because they contain an added gene through genetic engineering.
Transfer of genetic information from parent cells to future generations.
Organisms that receive their nourishment by eating other organisms e.g. plants.
A cell that houses foreign molecules or viruses and supports them using its own metabolism.
An individual resulting from a cross between two genetically unlike parents.
When two organisms from different species mate and produce offspring with some characteristics from each species.
Portions of DNA that don't have genes with an obvious function.
An arrangement of homologous chromosomes according to their size to form a chart.
The changing of a gene so that that organism loses a specific characteristic.
A collection of cloned DNA fragments as a group representing the entire genome.
Certain genes are known to be inherited together because they are so close to one another on the same chromosome.
Includes all loci (in DNA molecule) that can be connected (directly or indirectly) by linkage relationships; equivalent to a chromosome
Depending on how often certain characteristics are seen to appear at the same time in an organism, it's possible to predict where on a chromosome their genes may be found.
The position of a gene on a chromosome.
Meiosis (reduction division)
The process a cell's nucleus must go through to make sex cells (gametes) with half the number of chromosomes present in the original cell.
All the reactions controlled by enzymes needed to sustain life.
An organism that can only be seen using a microscope and not with the naked eye e.g. bacteria.
Mitosis (cell division)
The process through which cells multiply by one cell giving rise to two identical daughter cells.
the study of molecules that are found in cells.
A cell or organism that has been genetically changed as a result of mutation.
Something that is capable of producing a genetic mutation (change), by causing changes in the DNA of living organisms.
Any change that changes the nucleotide bases in the genetic material (DNA) of an organism or cell.
A technique used to cause mutations to take place in crops to introduce the desirable genes and therefore the trait into the plant.
The centre of living cells that contains DNA. It therefore controls the cell's life functions and heredity.
The four chemical building blocks (Adenine, Guanine, Cyotosine and Thymine) that make up DNA.
All the different cell components surrounded by the cell membrane that make up a cell. Many of these replicate as the cell replicates.
Any living plant, animal, bacteria, fungus, virus, etc.
any organism or microorganism that causes disease by invading the body of another organism.
refers to the outward appearance or characteristics of an organism including behavior which is determined by the DNA of its genotype.
a combination of reactions that take place in both the light and dark to produce carbohydrates in plants.
A compound made out of a string of amino acids and folded into a particular shape joined by peptide bonds. Each protein has a specific function, with some having a structural role and others acting as enzymes and speeding up chemical reactions.
the phenotype that only shows up in the offspring if the dominant allele is not inherited.
DNA formed by genetic material being arranged into a new combination.
The joining of genes, sets of genes, or parts of genes, into new combinations.
A gene that is inserted into DNA so that cell will "report" (to researchers) if a linked gene is functioning properly in the transgenic organism.
Viruses that replicate by making DNA from RNA (instead of the other way around) and therefore contain RNA in their virions.
Ribonucleic Acid (RNA)
A single-stranded nucleic acid normally used to make proteins. It is made up of nucleotide units containing the bases adenine, cytosine, guanine, and uracil (instead of thymine).
Choosing and growing specific individual plants or animals with desirable characteristics.
For those species with two sexes, these chromosomes determine the sex of the organism.
Known as all the "body cells" except the gametes or sex cells. Each somatic cell contains a full set of chromosomes, whereas sex cells only contain half.
A physical characteristic such as size, shape, taste, colour, disease resistance.
The portions of messenger RNA (mRNA) that are produced as a result of gene expression (transcription).
The process in which DNA is transferred from a donor to a host cell
usually the insertion of a specific gene into a specific variety.
The DNA that is to be inserted into the genome of a host cell using insertion techniques.
An organism with cells that contain one or more genes originating from a source other than the organisms parents i.e. a different species. These genes are artificially inserted into a specific variety.
The growth of abnormal tissue with no useful function to the organism. Tumors are known either as malignant or benign. Malignant tumors are known to grow continuously and have the ability to invade healthy tissues, eventually leading to death. Benign tumors tend to stop growing once they reach a certain point. And normally don't result in death.
Type 1 diabetes
This form of diabetes used to be known as juvenile or insulin-dependent diabetes. It is the form of diabetes disease that usually strikes young people, where the body's immune system destroys the insulin-producing cells of the pancreas.
Type II Diabetes
The form of diabetes disease that usually strikes people who are older than 40 years old. In many cases the adults' body tissues become insensitive to insulin. This type of diabetes is also known as "adult onset diabetes" or "non-insulin-dependent diabetes".
Anything that has the ability to trigger an animal's immune system without causing the animal to become sick. The animals' immune system is then given a chance to defend itself against the disease causing agent should it later enter the body.
A particle that can only reproduce if inside the living cells of other organisms; a virus is not a cell. Most viruses are made up only of genetic material
either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid)
and a protein coating. This assembly of material is known as a nucleoprotein.
Organic compounds that the body needs in very small amounts for normal growth and maintenance of good health to take place. They play important metabolic roles. There are two groups of vitamins, the fat soluble and the water soluble. Vitamins A, D, E, and K are fat soluble while vitamin C (ascorbic acid) and the vitamin B complex group are water soluble.
The typical form of an organism as one would expect to find it in nature. Those organisms that are not wild type strains differ due to domestication, natural mutation, or laboratory mutation.
The female sex chromosome. In species that have sex chromosomes that differ to one another this chromosome usually occurs as a pair in each female cell (i.e. XX in humans), and unpaired in each male cell (i.e. XY in humans).
The male sex chromosome in species in which males have two sex chromosomes that differ to one another.
An egg cell that comes from fertilization. It contains the complete set of chromosomes received from the union of the male (sperm) and female (egg) sex cells. The zygote develops into the organisms adult body.
Young Science Communicators Writing Initiative:
In an initiative to offer a platform to exercise skills in science communication, PUB commissioned a group of young scientists to write popular articles on various topics relating to biotechnology applications. Read their on articles on topics including sustainable energy, aquaculture, palaeogenomics, and more... Click here to view.
Previous PUB Quarterly Newsletters:
Shedding Light on Human Genetic Diversity
A paper detailing the the Southern African Genome Sequencing Project and its results was published in the journal Nature.
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